Peroxide and peroxyacid compounds, such as hydrogen peroxide and carbamide peroxide, have been disclosed as useful in teeth whitening compositions, Application of UV or visible light from, e.g., Argon lasers, has been employed to accelerate whitening after application of peroxide compositions to the teeth. Additionally, whitening compositions have been described that include compounds capable of absorbing light and converting it to heat or chemical energy, such as the metal-ligand complexes and metal chelate precursors described in U.S. Pat. No. 6,343,933 to Montgomery et al.
Red dyes have also been employed to absorb visible or UV energy and produce heat in a bleaching composition as described, e.g., in U.S. Pat. No. 6,485,709 to Banerjee et al. This patent also describes attempts to further enhance such compositions by adding metal ions, an organo-metallic enzyme (e.g., catalase), or using high pH (e.g., above 7) to destabilize or activate the decomposition of hydrogen peroxide. Teeth whitening compositions have also been described that include violet or blue-violet dyes to counter-stain yellow teeth in U.S. Pat. No. 6,030,222 to Tarver. Rhodamine B dye has been employed in a teeth whitening composition as described in WO 02/22097 to Verheyen et al.
Tooth sensitivity following treatment, and the time required for teeth whitening compositions (typically requiring about an hour of time or multiple applications or both), however, remains a significant drawback.